Deep-sea diving system

ABSTRACT

A diving system that includes a flexible breathing gas reservoir designed to float at sea surface and including a power supply circuit through which a diver is connected to the flexible reservoir to obtain breathing gas. The system includes a device for interrupting the power supply circuit which interrupts the breathing gas supply of the diver when the pressure in the reservoir is lower than a predetermined threshold.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to underwater diving systems comprising abreathing gas reservoir that remains at the water surface.

[0003] 2. Description of Background and Relevant Information

[0004] In systems of the above-mentioned type, commonly referred to as“hookah diving systems,” the diver is connected to the reservoir by asupply circuit having a hose that is generally relatively long to enablethe diver to move in a certain zone around and beneath the reservoir.Unlike the diving systems in which the diver takes the air reservoirwith him under water, the diver who uses a hookah system only takesunder water the hose whose free end is provided with a mouthpiece or afacial mask.

[0005] There are various types of reservoirs for the hookah systems.Some of them are rigid, others are flexible. Among the advantages of theflexible reservoirs is the fact that the reservoir is lightweight andcan be made very compact when the system is not in use. This makes iteasier in particular to transport the system to the practice site.

[0006] The principle of a hookah system having a flexible reservoir isdescribed, for example, in the document GB-2,164,259. This documentprovides that an operator, who remains at the surface, must make surethat the reservoir is kept full of air at all times. Therefore, thisimplies that the reservoir is constantly connected to a (manual ornon-manual) pump, and that this pump is constantly actuatable.Therefore, one can conclude that this diving system is adapted to beused from a boat or from a platform floating at the water surface.

[0007] A similar system is described in the document EP-A-437 948. Thisdocument specifies that the flexible reservoir is preferably encircledby a ring of buoyant material.

[0008] In any case, it is indeed desired that the reservoir continuefloating at the surface, even at the end of the dive, not only toprevent the diving system from sinking, but particularly to form a buoyon which the diver can take support at the end of the dive. However,since the reservoir is flexible, its volume is going to decrease,particularly at the end of the dive, if the diver breathes all of thegas contained in the reservoir.

[0009] The solution of the document GB-2,164,259 consisting of providinga second operator on a platform at the surface is not satisfactory,insofar as this limits the autonomy of the diver who cannot dive wherehe wants and who is forced to be accompanied by a person who cannotdive. The solution of the document EP-1-437 948 is not satisfactoryeither insofar as the ring of buoyant material can prove cumbersome whenone wishes to store the diving system after returning to shore.

SUMMARY OF THE INVENTION

[0010] The object of the invention is to propose a diving system whosedesign is simple and practical, and which makes it possible toguarantee, by means of a compact device, that the reservoir continuesfloating at the water surface, even at the end of the dive.

[0011] To this end, the invention proposes a diving system comprising aflexible breathing gas reservoir adapted to float at the water surfaceand comprising a supply circuit through which a diver is connected tothe flexible reservoir in order to draw breathing gas therefrom, whereinthe system comprises a device for shutting off the supply circuit whichinterrupts the breathing gas supply to the diver when the pressureinside the reservoir drops below a predetermined shut-off threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Other characteristics and advantages of the invention will becomeapparent upon reading the description that follows, with reference tothe annexed drawings, in which:

[0013]FIG. 1 schematically shows a diving system according to theteachings of the invention;

[0014]FIG. 2 schematically shows an example of embodiment of a supplyshut-off device.

DETAILED DESCRIPTION OF THE INVENTION

[0015]FIG. 1 shows a diving system 10 comprising a breathing gasreservoir 12 under pressure, and comprising a supply circuit 14 whichenables the diver underwater to breathe the gas contained in thereservoir 12. According to the invention, the reservoir is a flexiblereservoir, and it is adapted to remain at the water surface. The supplycircuit 14 is very schematically represented by a supply hose 16 that isconnected to the reservoir, and the free end of which is provided with amouthpiece 18 preferably incorporating a reducing valve through whichthe diver can draw the breathing gas contained in the reservoir 12. Thediving system 10 also comprises means (not shown) that allow filling thereservoir with a breathing gaseous mixture such as air. These means canbe a single device for connecting to an air compressor. They can also bemeans adapted to be carried with the reservoir. For example, air isstored in the reservoir 12 under a maximum pressure of 10-20 bars. Incertain cases, a two-stage pressure reducing valve system can beprovided, particularly if the air storage pressure is high.

[0016] The reservoir 12 is a flexible reservoir in the sense that atleast some of the walls that demarcate it are capable of becomingdeformed, making it possible to decrease or increase both the internaland external volumes of the reservoir. Preferably, however, thereservoir has an inextensible maximal volume, which is reached, forexample, upon an absolute pressure on the order of 1.2-1.5 bars. Fromthis pressure, the reservoir will have reached an “inflated” state and,beyond, its volume will no longer increase significantly. Conversely,the reservoir will preferably have a very small external volume once itis “deflated.”

[0017] In the example shown, the reservoir is a fully flexible reservoirconstituted of a bag made of a waterproof fabric. This construction isboth simple and lightweight, and it allows making the reservoirextremely compact when not in use. Indeed, the reservoir 12 can becompletely deflated and folded. The constituent material can also be aflexible and impervious plastic material (for example, polyurethane), orthe reservoir can be constructed with a multilayered material includinga first layer of material ensuring the mechanical resistance to pressureand at least one impervious inner layer.

[0018] Alternatively, the reservoir can be only partially flexible.Thus, it could comprise at least one rigid or semi-rigid surface makingit possible to attach accessories such as carrying straps or systems forconnecting to a reservoir filling device, and even to attach the meansfor connecting the supply circuit 16. The reservoir could also have twoopposing rigid walls joined to one another by flexible walls, such thatthe reservoir is substantially parallelepipedic in the position of use,but that it is in the form of a thin, rigid flat rectangle in theposition of storage. The flexible walls could also be constituted ofrigid elements articulated between each other.

[0019] Similarly, in the example shown, the reservoir 12 forms theentire emerged portion of the diving system. But the system could beprovided to comprise other components or accessories. By way of example,the diving system can be provided to comprise a device for filling thereservoir, for example, a motorized pump, or a human-actuated pump, suchas a manual pump. This pump could also be integrated in a compartmentaffixed to the reservoir. In this case, the reservoir can play the roleof a float by providing these accessories with a buoyancy reserve inorder to maintain the assembly at the water surface, without it beingnecessary to provide a special flotation device. According to anotherexample, the reservoir can be associated with a rigid or semi-rigidstructure forming, in combination with the reservoir, a hydrodynamicfloat on which the diver can take support in order to swim at the watersurface with a minimum of effort. Still further, the diving system canbe provided to comprise, in addition to the flexible reservoir accordingto the invention, at least one auxiliary reservoir that can be rigid orflexible.

[0020] In any case, one understands the advantage for the float tomaintain its full floating ability, or at least a significant portionthereof.

[0021] Thus, according to the invention, the diving system 10 comprisesa device 20 for shutting off the supply circuit 14 which, below apredetermined pressure threshold in the reservoir 12, prevents the diverfrom drawing air from the reservoir. The predetermined pressurethreshold is determined as a function of the pressure necessary formaintaining the reservoir 12 in an “inflated” state in which itconserves its full or at least a significant portion of its floatingability.

[0022] This predetermined shut-off threshold can be, for example, anabsolute pressure threshold in the reservoir. It can thus be set to anabsolute pressure value comprised between 1.2 and 1.5 bars. It can alsobe a relative pressure threshold in the reservoir in relation to theatmospheric pressure, the shut-off device imposing in the reservoir apressure which is greater than the atmospheric pressure, for example,50-200 millibars.

[0023]FIG. 2 shows an example of a shut-off device that is capable ofbeing used for implementing the invention. The shut-off device 20 hereis a calibrated valve made in the form of a membrane differentialpressure valve, which member is known per se, and it is shown in theposition for shutting off the supply.

[0024] The valve thus comprises a box 22 that imperviously divided intotwo chambers by a membrane 24: a circulation chamber 26 and a controlchamber 28. The control chamber 28 is open to the atmosphere, such thatthe pressure prevailing therein is the atmospheric pressure. Thecirculation chamber 26 is in turn divided into two compartments: anupstream compartment 30 that is connected to the interior of thereservoir 12, and a downstream compartment 32 to which the supply hose16 is connected. The two compartments 30, 32 communicate at the level ofa circular seat 34 arranged opposite the membrane 24. The membrane 24carries a flat shutter 36 that is capable of pressing itself against theseat 34 in order to interrupt any fluid circulation between the twocompartments 30, 32. Finally, a compression spring 38 is arranged in thecontrol chamber 28 to prestress the shutter 36 toward the seat 34.

[0025] When, on each side of the shutter 36, the force of the airpressure in the reservoir 12 is greater than the sum of the force of theatmospheric pressure and of the prestress of the spring 38, the shutter36 is separated from the seat 34, and air can circulate from thereservoir 12 toward the supply hose 16, therefore toward the diver.Conversely, as soon as the force of the air pressure in the reservoir 12drops below said sum, the shutter 36 is pressed against the seat 34 bythe spring 38, which interrupts air circulation as shown in FIG. 2. Thediver can no longer continue to empty the reservoir; therefore, airpressure within the reservoir cannot drop below a threshold value, suchthat the reservoir cannot deflate, and it maintains its floatingability.

[0026] Naturally, the embodiment of the shut-off device that is proposedhere is only a non-limiting example. Other known shut-off devicesfulfilling the same function can be used for implementing the invention.

1-7. (Canceled)
 8. A diving system comprising: at least one breathinggas reservoir adapted to float on a water surface, said breathing gasreservoir being at least partially flexible; a supply circuit adapted toconnect the flexible reservoir to a diver for enabling the diver to drawbreathing gas from the reservoir; a device for shutting off the supplycircuit which interrupts the breathing gas supply to the diver when thepressure inside the reservoir drops below a predetermined shut-offthreshold.
 9. A diving system according to claim 8, wherein: theshut-off threshold corresponds to a predetermined difference in pressurebetween the atmosphere and the interior of the reservoir.
 10. A divingsystem according to claim 8, wherein: the shut-off threshold ispredetermined so as to maintain the reservoir in an inflated state. 11.A diving system according to claim 8, wherein: the shut-off devicecomprises a calibrated valve.
 12. A diving system according to claim 8,wherein: the shut-off device is positioned within the supply circuit.13. A diving system according to claim 8, wherein: the flexiblereservoir is coupled to accessories of the system, to which the flexiblereservoir provides a buoyancy reserve.
 14. A diving system according toclaim 13, wherein: the system comprises an auxiliary reservoir.